PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Ciliary Body”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1976

[Acetylcholine in the bovine ciliary body and the cholinergic action of pilocarpine].

The authors have determined the acetylcholine (ACh) content in bovine ciliary bodies. One of the ciliary bodies was subjected in vivo to the influence of an aqueous solution of pilocarpine HCl 3 p. 100 which was instilled in the conjunctival cul-de-sac (ten times at a dose of three drops every three minutes). The contralateral ciliary body of the same animal served as a control for the ACh concentration. Enucleation was performed one hour after the last instillation. The average concentration of ACh estimated in 13 control ciliary bodies was 0,40 mug of ACh, and in 13 pilocarpinised eyes 0,50 mug of ACh (for 150 mg of tissue). The questions concerning the inactivation of pilocarpine and the source of augmentation of cholinergic tone in the pilocarpinised eyes have been discussed in previous communications.

Acetylcholine↗
PubMed1979

The transport of para-aminohippuric acid by the ciliary body and by the iris of the primate eye.

Para-aminohippuric acid (PAH) accumulates against a concentration gradient in the ciliary body and independently in the iris of the rhesus monkey eye. This accumulation is inhibited by incubation of 0 degrees C and shows saturation kinetics in both tissues. Cyanide, ouabain, dinitrophenol, iodopyracet, and probenecid effectively depress PAH uptake in both tissues, but anaerobic incubation conditions have little effect on uptake in either tissue. The washout of preaccumulated PAH occurs 2.5 times faster from the iris than from the ciliary body. The effects on washout of 10(-4)M PAH, 0 degrees C, and 10(-5)M dinitrophenol are consistent with washout occurring by a diffusional mechanism in both tissues, with some reaccumulation occurring in the ciliary body only. In addition, nonsaturable uptake of PAH, studied in both tissues under high PAH concentrations, also occurs significantly faster in the iris than in the ciliary body. The kinetic analysis of active PAH uptake in both tissues is discussed in terms of initial uptake and in terms of a steady-state model. This steady-state model compensates for some technical problems in applying in vitro incubation techniques to primate tissues and also includes a correction for the additional exchange processes that affect the two tissues differently. Results of the kinetic analysis suggest that, at least to an order of magnitude, iris uptake is significant with respect to ciliary body uptake.

Aminohippuric Acids↗
PubMed1979

Cholic acid accumulation by the ciliary body and by the iris of the primate eye.

Cholic acid accumulates in both the ciliary body and the iris of the primate eye during in vitro incubations at 37 degrees C for 1 hr. Incubation at 0 degrees C depresses uptake in both tissues. The washout of preaccumulated cholic acid occurs some 3.4 times faster from the iris than from the ciliary body. The mechanism of cholic acid accumulation in both tissues is less sensitive to inhibition by high iodipamide concentrations and also is less sensitive to inhibition by high hippurate concentrations than the mechanism of p-aminohippurate (PAH) accumulation. Therefore, although overlap may exist, the cholic acid--uptake mechanism differs from the PAH-uptake mechanism in both the primate ciliary body and the primate iris.

Animals↗
PubMed1979

Proton irradiation of malignant melanoma of the ciliary body.

This is our first case of malignant melanoma of the ciliary body treated with proton beam irradiation, a technique that we developed for irradiating choroidal melanomas. After 21 months of follow-up no growth of the tumour has been observed, and shrinkage of the tumour was noted on the follow-up photographs and by ultrasonography. The 32P uptake test, which was positive before treatment, turned negative 14 months after irradiation. The described technique of proton beam irradiation might offer an alternative for the treatment of ciliary body melanomas when the present techniques of iridocyclectomy cannot be applied because of the size of the lesion.

Ciliary Body↗
PubMed1978

Influences on the density of beta-adrenergic receptors in the cornea and iris--ciliary body of the rabbit.

By measurement of the specific binding of 3H-dihydroalprenolol, the densities of beta-adrenergic receptors on membranes prepared from homogenized corneas and iris--ciliary bodies of rabbits were studied. Sympathetic denervation, as a result of subconjunctival treatment with 6-hydroxydopamine, causes an increase in the density of beta-adrenergic receptors in membranes prepared from the ipsilateral iris--ciliary body but not the cornea. Topical treatment with epinephrine for 5 days causes a decrease in the density of beta-adrenergic receptors in membranes prepared from cornea and iris-ciliary body, whereas similar treatment with timolol causes an increase in the density of beta-adrenergic receptors. In the cornea, the decrease in receptor density that occurs following in vivo treatment with epinephrine is associated with a decreased ability to synthesize cyclic AMP, whereas the increase in receptor density that occurs following in vivo treatment with timolol is not associated with an altered ability to synthesize cyclic AMP. Our results indicate that the density of beta-adrenergic receptors in the anterior segment of the eye is inversely related to the level of adrenergic stimulation to the tissue but that the ability of a tissue to synthesize cyclic AMP does not necessarily parallel the change in receptor density.

Animals↗
PubMed1977

[The action of instilled physostigmine on the acetylcholine content of the bovine ciliary body (author's transl)].

The authors have compared the content of acetylcholine (ACh) of the two ciliary bodies (150 microgram of tissue) after the instillation of a stimulating dose of a 1% aqueous solution of physostigmine (10 applications of three drops at intervals of three minutes) into the conjunctival fornix of one eye. Kymographic measurements on guinea-pig ileum demonstrated an average elevation of the ACh content in the instilled ciliary bodies (0.48 microgram) against the controls (0.33 micron). The eyes were enucleated one hour after the last application.

Acetylcholine↗
PubMed1979

Scleral buckles and rotation of the ciliary body.

Angle closure glaucoma is a well-known complication of scleral buckling and it is of particular interest when it occurs in eyes with previously normal angles. Forward rotation of the ciliary body about the scleral spur has been postulated as one possible mechanism for such angle closure. Large buckles were used in macaque rhesus monkeys and histopathologic examination indicated rotation of the ciliary body about the scleral spur as the cause of angle closure. Pupillary block was not present and large choroidal detachments were not needed to produce the observed closure. The exaggerated buckles used do not allow these monkeys to serve as a clinical model and great caution is stressed in making clinical extrapolations.

Animals↗
PubMed1979

Bicarbonate ATP-ase in ciliary body and a theory of Diamox effect on aqueous humor formation.

Bicarbonate was found to stimulate ATP breakdown by rabbit or cat ciliary body-iris homogenates. Maximum HCO3- stimulation of ATPase with Tris-Hepes buffer occured at pH 8.0. Acid pH and chloride ions in the media reduced the activity of the HCO3--stimulated ATPase. The Km for ATP was 0.55 mmolar and for HCO3-, 20 mmlar. HCO3- ATPase was not inhibited by acetazolamide added to in vitro. It is postulated that ATPase represents the linkage step of energy donor mechanism and active CT secretion in acid aqueous humors (human, cat.) or HCO3- secretion in alkaline aqueous humor (rabbit, guinea pig). Inhibition of Cl- or HCO3- secretion by acetazolamide results from decreased intracellular HCO3- levels which, in turn, reduces the stimulation of the HCO3- ATPase.

Acetazolamide↗
PubMed1978

Gradients of proliferation of ciliary basal bodies and the determination of the position of the oral primordium in Tetrahymena.

The pattern of proliferation of new basal bodies in ciliary rows (somatic proliferation) in Tetrahymena was observed. Starved and refed cells were used, because proliferation in these cells is more pronounced than that under other circumstances. The formation of new basal bodies is locally determined by the position of "old" pre-existing basal body (short range determination). However, the probability of proliferation associated with any given "old" basal body differs very much. This probability is determined by the spatial coordinates of the particular region of the cell (long range determination); however some randomness in this process was also observed. Two different gradients of proliferation were found. The first gradient is circumferential with a maximum number of new basal bodies added in ciliary rows n, 1, 2 and 3 and the minimum number added in ciliary rows 7, 8 and 9. The second is an antero-posterior gradient with the highest number of new basal bodies added in the midbody region. Moreover, at least in some cases, new oral primordia first appear, as a random proliferation of new basal bodies adjacent to a few old cilia of ciliary row No. 1, resembling somatic proliferation. Then 2,3 or even more clumps of basal bodies appear, each having one old cilium posteriorly. These clumps, however, are not linear groups within the ciliary row but instead they form small fields of basal bodies. These findings suggest, that the same two-gradient system for new basal body addition operates during somatic proliferation and also determines the position of the new oral primordium as the site of the highest gradient value at the intersection of two gradients.

Animals↗
PubMed1979

Sites of breakdown of the blood-aqueous barrier after paracentesis of the rhesus monkey eye.

Sites of breakdown of the blood-aqueous barrier following rapid paracentesis have been investigated in rhesus monkeys with two independent procedures. (1) The entrance of fluorescein into the anterior and posterior chambers following paracentesis was studied in vivo in normal eyes, in eyes with laser-induced experimental glaucoma, and in totally iridectomized eyes. (2) Scanning electron microscopy was used to study the ciliary body and trabecular meshwork regions in normal eyes and paracentetic eyes. These investigations show that the ciliary body, particularly the anterior pars plicata region, is a source of secondary aqueous humor protein. In addition, the study shows reflux of blood into Schlemm's canal and plasma movement across the inner wall into the anterior chamber.

Animals↗
PubMed1977

Movement of horseradish peroxidase in the cornea, sclera and the anterior uvea.

The anterior chambers of rabbit, monkey and human eyes were perfused with horseradish peroxidase. The perfusion was started immediately after enucleation of the monkey and human eyes, while the rabbit eyes were perfused in situ after the animals had been killed. Comparative results were obtained after 1 h or perfusion and were mainly based on frozen sections. Intensive staining was found in the Descemet's membrane, the sclera and the iridial stroma, considerably more than in the corneal stroma and in the ciliary body base. In the vervet monkey and human eyes only traces of peroxidase reaction products were seen in the stroma of the ciliary body base. The movement of the protein tracer from the anterior chamber into the corneal stroma is probably dependent upon vesicular transport across the corneal endothelium. The Discemet's membrane was interpreted to be more porous than the corneal stroma. A transcorneal and a corneo-scleral movement appeared to be more efficient than the uveo-scleral one, at least in the vervet monkey and the human eyes.

Animals↗
PubMed1978

An experimental model of acute immune-complex uveitis.

We developed an experimental model of anterior uveitis by injecting ovalbumin or bovine serum albumin into the anterior chamber of sensitized rabbits. All the eyes showed leakage of serum proteins into the aqueous humor within 30 min. and developed uveitis within 24 hrs. which lasted at least a week. On histological examination, large numbers of polymorphonuclear (PMN) leucocytes and only occasional mononuclear cells were seen in the iris, the ciliary body and the irido-corneal angle. Immunohistological examination revealed 7s gamma globulin in the walls of blood vessels, in the interstitium and inside the PMN leucocytes. Contact radiographs of eyes challenged repeatedly showed extensive neovascularization of the iris and ciliary body.

Animals↗
PubMed1979

Ocular findings in metachromatic leukodystrophy. An electron microscopic and enzyme study in different clinical and genetic variants.

Histopathological studies of the eyes from three patients affected with the infantile form of metachromatic leukodystrophy (MLD) showed the storage of metachromatic complex lipids in the retinal ganglion cells, in the optic nerve and the ciliary nerves, as well as the storage of a mucopolysaccharide-like material in the nonpigmented epithelium of the ciliary body. The lesions were limited to the optic, ciliary, and sensory nerves in a fourth patient with the juvenile form of the disorder. These morphological aspects, which are probably related to differences in sulfatase A activities, may explain the variability of the ocular manifestations in metachromatic leukodystrophy. Seven children affected with infantile MLD or with mucosulfatidosis were examined by conjunctival biopsy. Typical lesions of the sensory nerves were obvious and allowed the diagnosis of the disease. However, it seemed impossible to separate the different forms by histopathological studies only. The tear enzymes were assayed in most of the cases and demonstrated a profound deficiency of arylsulfatase A, or of arylsulfatase A and B, in the classical MLD and in mucosulfatidosis, respectively.

Cerebroside-Sulfatase↗